"Pure" monocytic or histiomonocytic leukemia: a revised concept

Area of Science:

• Hematology
• Oncology
• Cytochemistry

Background:

• Acute leukemia diagnosis relies on morphology and cytochemistry.
• Distinguishing subtypes of acute leukemia is crucial for prognosis and treatment.
• Monocytic leukemia presents diagnostic challenges due to overlapping features.

Purpose of the Study:

• To characterize 10 cases of
• pure
• monocytic leukemia based on cytochemical and morphological findings.
• To evaluate the treatment response and potential classification of these cases.

Main Methods:

• Cytochemical staining (Sudan black, peroxidase, esterases, PAS, Oil red O, beta-glucuronidase) of bone marrow aspirates.
• Light and electron microscopy for cell morphology assessment.
• Analysis of patient response to various chemotherapy regimens (prednisone, vincristine, Adriamycin, cytosine arabinoside).

Main Results:

• All 10 cases were Sudan black and peroxidase negative, but positive for alpha-naphthyl acetate esterase.
• Morphology was consistent with monocytic or histiocytic leukemia.
• Most patients achieved remission with prednisone/vincristine or Adriamycin; cytosine arabinoside showed poor efficacy.

Conclusions:

• The distinct cytochemical profile and morphological features support classifying these cases as histiomonocytic leukemia.
• This classification may aid in objective diagnosis and treatment strategies for acute leukemia.
• Further research is warranted to validate this subtype and optimize therapeutic approaches.